Mould growth prediction with a new biohygrothermal method and its application in practice

In buildings growing conditions for mould fungi can occur and cause fungus infestation. The possible danger for the occupants of dwellings lies in the production and spreading of pathogens (disease causing agents). Therefore, consequent measures have to be taken to avoid health dangers that result from mould fungi in buildings. A strategy has to be set up that focuses on the growth conditions for mould fungi and also considers the complex transient processes of building physics. The boundary conditions for the growth of fungi are temperature, humidity and substrate conditions which have to be simultaneously favourable over a certain period of time. In the Fraunhofer-Institute of Building Physics (IBP) in Germany a biohygrothermal procedure is developed, which allows the prediction of mould growth under transient boundary conditions. In order to differentiate the mould fungi according to the health dangers they may cause, so called hazardous classes were defined. This new method will be described with its new features and its limitations. Typical results of this model are shown within an example. Furthermore the significance of the results are discussed.